mysql 如何同时查询多个 count

select count(commentId ),commentId from ( select * from t_like where commentId in ('1','2','3','8','10') and status = 1 ) group by commentId

不知道这样可不可以实现你要的

第一种

SELECT (count(*) FROM `bbs_thread` WHERE uid = 7) AS mythreads, (COUNT(*) FROM bbs_post WHERE uid = 7) AS myposts

第二种

SELECT (count(*) FROM `bbs_thread` WHERE uid = 7) AS mythreads, COUNT(*) AS myposts FROM bbs_post WHERE uid = 7

userid在两个表中都应该是唯一的吧，你group by是什么意思呀？

如果需要获得结果的行数，可以使用select count(*) from table1 a,table2 b where a.userid=b.userid.

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